Pot furnace



Patented Nov. 5, 1929 UNi'rsDl s'TArss LEON C. KOENIG,

OF CUDAI-IY, WISCONSIN, ASSIGNOR TO I-IEVI 'DUTY ELECTRIC :Por FURNACE Application led April 24,

My invention relates broadly to furnaces and more particularly to electric furnaces of the pot type.

One of the objects of my invention is to provide a construction of pot type furnace in which the heat flow from the pot of the furnace to the metallic top plate of the furnace is prevented by interposing a non-metallic, flexible and compressive packing between the flange of the pot and the supporting proj ection of the t-op plate of the furnace.

Another object of my invention is to provide a sealing means between the annular periphery of a pot type furnace and the heating system thereof, by applying a packing ring between the periphery of the upper edge of the pot and the heating chamber for distributing the weight of the pot and its contents more uniformly on the supporting projection of the top plate.

Still another object of my invention is to provide an arrangement of highly compressive packing ring disposed between preformed peripheries of the heating chamber and the pot furnace in order to prevent molten or fluid material, such as lead or fluid salts, or the fumes thereof, from getting into the furnace chamber outside the pot where such fluids or gases might be detrimental to the furnace walls or heating means.

The structure of my invention will be more fully understood from the specification hereinafter following by reference to the accompanying drawings, in which Fig. 1 is a transverse section through a pot type furnace partly in elevation showing my invention applied thereto; and Fig. 2 is an enlarged section through that portion of the pot furnace of my invention wherein the packing ring is lodged.

'Referring to the drawings in'more detail, the walls of the furnace are formed from a refractory material 1 enclosing the furnace chamber 20. Reference character 9 indicates the top plate which may be formed from cast iron supporting a suspended pot 4, which may be of cast iron, pressed steel or cast of a non-oxidizing metal. Interposed bet-ween the downward extending annular flange 4b of pot 4 and the upward turned sup 1928. VSeiialNo. 272,365.

porting portion 8 of top plate 9, is a packing ring 6 formed from such material as asbestos, either in the twisted or braided form.

The furnace is shown heated electrically by means of coils 3 housed within the refractory walls l, though any other suitable furnace chamber heated by fuel may be used. The upwardly extending annular peripheral portion 8 of top plate 9 is preferably grooved orv shaped at its extremity to better support and compress the packing ring 6. The annular upstanding edge 8 is actually dished or formed with a concave upper peripheral face which confines the compressible ringmemher 6 to a. definite position with respectl to the pot type furnace. The underside of the annular peripheral edge 4b 'of the pot 4 is concave downwardly while the upper peripheral edge 7 is concave upwardly. 6k

The weight of the pot 4 with its contents highly compresses the flexible packing 6, which distributes the weight more uniformly on'the supporting upwardly extending portion 8 of top plate 9 than would exist where a comparatively -rough casting having such upturned portions would bear only in a few locations on the underside of lip 4a. This reduces the stresses that wouldotherwise be set up by an unequal distribution of weight. The same compressive action tends to seal the furnace chamberv from inflow of any fluid such as molten lead, molten salt, etc.

The -packing ring disposed between thel annular periphery of the pot furnace and the heating chamber has been found to be extremely'practical in cutting down heat losses by radiation due to breaking up the heat flow by direct contact between the pot and the top plate of the furnace. It has been found eEective also in sealing the furnace chamber from the influx of gases', fluids, etc. I

Heretofore it has been proposed to cement by any material such as fire clay, the unctions between the pot and the top plate. The inequalities of expansiomhowever, between the pot which obviously may beat arhigh temperature andfthe4 top plate of the furnace, which may be at a comparatively lower temperature7 tends to break up such refractory cement and destroy its effectiveness. The

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compressible packing ring which I employ forms a sealing Zone which is substantially permanent in character, not subject to cracks and breakage under conditions of tempera ture change.

The top plate 9 may fit telescopically over th-e outer plate 2 of the furnace as shown at l()y for centeringthe plate on the furnace structure. The annular rim aa-tb isvso-shaped as to form a substantially inverted U having a rim seat 5 and a skirt portion lb for'conllining the compressible ring member 6 between the rim seat 5 and the coactingseat.

The structure of my invention. has proven highly'practicalin use, and while' I'have de'- scribed a preferred embodiment of -niyinven` tion, I desire thatitbe' understood that modiflcations may be made and that no limitations are intended other than are imposedby the scope of: the appended claims.

What I claim as new and desire to secure by Letters Patentof the United States is as follows:

l. In a pot'type furnace a housing termi# Ynating in an upstandin'g annular member, a

seat formed in said annular'member, said seatv extending upwardly at each edge thereof and having a' central portion disposed' at a level lower thanthe level ofthe edges of the seat, a pot type receptacleY having a rolled-over edge terminating'inV a depending skirt for providing an annular' seat beneath said rolled-over edge, and an annular yieldable' gasket member disposed between the' seat on said annular member and the? seat'` beneath said rolled-over' edge for' sealing the connec-v tion between said pot' type receptacle and said 1' housing.'

2.' In a pot type furnace avhousing'termil nating in an' upstanding'annularmember, a concave seat'formed'in said upstanding annular member, a pot type receptacle having.

an annular rim of U- shaped contour extending' over said` upstan'ding annular member, the underface of said: rim being'concave downwardly in cooperative'. alignment with the con'caveseat` on said upstanding'annular member, and a compressible gasket secured 1n the concave seat` 1n said upstand1ngannularmember andoccupyinga position between said seats for sealingL the passage therebe-V tween.A

3. In'a pot type furnace, a=furnace chamber, a top plate member in said chamber' terminating in a centralannular rim, a pot depending concentrically Within'said rim, said potliaving anannular edge thereon, comple-` mentary curved faces on the said. annular edge of'saidfpoti andthe annular rim of said top-'plate member, and a compressible gasket conlin'edwithin a concave' seatin. the annular-` rnn of said to'p'plate/member and secured` between said lcompflenfientary faces;

4.. In'apot type furnace,w-a'furnace cham-- ber, a top plate on said chamber, said plate locatedbetween saidfcomplementary faces forl sealing said 'chamber' with Vrespectt'o'said pot. InA testimony whereof I aliiX my signature.

LEON C. KOENIG. 

